Implement Action#output (delegates to env.output)

spec/producer/core/action_spec.rb

@@ -17,5 +17,12 @@ module Producer::Core
         expect(action.arguments).to eq arguments
       end
     end
+
+    describe '#output' do
+      it 'delegates to env output' do
+        expect(action.env).to receive(:output).with(:content)
+        action.output :content
+      end
+    end
   end
 end

spec/producer/core/actions/echo_spec.rb

@@ -7,7 +7,7 @@ module Producer::Core
     subject(:echo)  { Actions::Echo.new(env, text) }
 
     describe '#apply' do
-      it 'writes the given string to env.output with a record separator' do
+      it 'writes the given string to env output with a record separator' do
         echo.apply
         expect(env.output.string).to eq "hello\n"
       end